Deflectable jumper strip

ABSTRACT

A jumper strip for terminal blocks or the like comprises in one embodiment a pair of fastener engaging portions coupled together by a resiliently deflectable upstanding arched portion so that the spacing between the apertures may be selectively varied by exerting suitable pressure on the arched portion. The strip may be disposed over terminal screws having a center to center spacing slightly greater or smaller than the spacing between the apertures in the strip whereby upon release of the arched portion the strip is urged against the shank of the terminal screws and retained in position during the loosening and tightening of the screws. In another embodiment, a plurality of such fastener engaging portions are resiliently joined one to another in strip fashion to provide a multiple terminal shorting bar or jumper strip. The apertures are joined to a common edge of the jumper strip by a slot which may be aligned with or offset from the axis of the aperture.

ited States Patent [191 1* rey [111 3,831,129 [451 Aug. 20, 1974DEFLECTABLE JUNIPER STRIP [75] Inventor: William G. Frey, Union, NJ.

[73] Assignee: Thomas & Betts Corporation,

Elizabeth, NJ.

22 Filed: Sept. 14,1973

21 Appl.No.:397,243

[52] US. Cl. 339/19, 339/242, 339/252 R [51] int. Cl H011 31/08 [58]Field of Search 339/19, 222, 242, 22, 252;

24/81 B, 81 CC, 87 TB 3,728,656 4/1973 Neuber Primary ExaminerBobby R.Gay

Assistant Examiner-Robert A. Hafer Attorney, Agent, or Firm-DavidTeschner; Jesse Woldman ABSTRACT A jumper strip for terminal blocks orthe like comprises in one embodiment a pair of fastener engagingportions coupled together by a resiliently deflectable upstanding archedportion so that the spacing between the apertures may be selectivelyvaried by exerting suitable pressure on the arched portion. The stripmay be disposed over terminal screws having a center to center spacingslightly greater or smaller than the spacing between the apertures inthe strip whereby upon release of the arched portion the strip is urgedagainst the shank of the terminal screws and retained in position duringthe loosening and tightening of the screws. In another embodiment, aplurality of such fastener engaging portions are resiliently joined oneto another in strip fashion to provide a multiple terminal shorting baror jumper strip. The apertures are joined to a common edge of the jumperstrip by a slot which may be aligned with or offset from the axis of theap- V erture.

3 Claims, 9 Drawing Figures PATENIEDAUEZOIW 3.831.129

SHEET 1 W 2 FIG, 4

DEFLECTABLE JUMPER STRIP BACKGROUND OF THE INVENTION snapped into placewherein upon removal of the force on the arched portion of the jumperstrip the strip will tend to return to its undeflected state causing theside walls of the fastener receiving apertures to bear tightly againstthe terminal block screws. The jumper strip is thus maintained inposition throughout the tightening and loosening of such terminal blockscrews so that the loss or displacement of such strip is effectively andsimply prevented. The slots joining the apertures in the strip to acommon edge of the strip may either be aligned with the apertures oroffset therefrom which, in the latter case, will tend to further lockthe strip onto the terminal block or the like. The degree of forcerequired to selectively deflect the arched portion of the minals, or bythe use of a solid shorting bar suitably ap- I5 jumper strip may bereadily controlled by varying the ertured to correspond to the spacingbetween the terminals to be shorted or connected together. The formermethod is quite tedious and time consuming and requires the unwrappingof the wire from the terminal post to open or otherwise interrupt suchconnection. In the latter case, the strips must be formed with slottedapertures having a center to center spacing corresponding to the spacingbetween the terminals to be shorted or connected. Thus, wheredifferently spaced terminals are employed a rather large quantity orstock of such shorting strips must be maintained to ensure the properfit in any particular case. Additionally, when assembling such prior artstrips to a terminal block or the like, the strip must be continuouslysupported in the desired position against the shank of the terminalscrews to be connected or shorted together until the heads of the screwsor threaded fasteners have been brought into sufficient contact with thestrip to hold the strip in the desired position. Where such terminalblock is disposed in a generally vertical plane in an electricalassembly or the like, extreme care must be exercised when loosening theterminal screws or fasteners to disengage the strip therefrom to avoidhaving the strip fall away from the terminal block and contactelectrically energized terminals or elements adjacent thereto. Attemptsto avoid this problem by supplying an unslotted aperture in the jumperstrip causes additional inconvenience in that the terminal screws mustbe completely removed from the terminal block to provide for theassembly or disassembly of the strip to and from the terminal block.

SUMMARY OF THE INVENTION The invention overcomes the problems andlimitations noted above with respect to prior art devices by providing adeflectable jumper strip which is more reliable, convenient, efficient,and safer than such prior art devices. The strip is formed with aresiliently deflectable upstanding arched portion disposed intermediateeach two apertured fastener engaging portions each having aperturesspaced from one another a first given distance when the arched portionis undeflected and a second given distance when the arched portion iseither compressed or expanded in response to a force applied thereto.The strip may thus be employed to bridge two or more terminals whosecenter to center spacing corresponds generally to the deflected spacingbetween the apertures in the strip by subjecting the arched portion to asuitable force to cause the slots in the jumper strip to be aligned withthe shank portion of the threaded fasteners in the terminal block or thelike. The strip may thus be urged against the terminals and height,width, and physical configuration of such arched portion therebyeffectively controlling the resiliency thereof. It is therefore anobject of this invention to provide an improved jumper strip.

It is a further object of this invention to provide a deflectable jumperstrip for interconnecting terminals of a terminal block or the like.

It is another object of this invention to provide a selflocking jumperstrip.

It is yet a further object of this invention to provide means fordeflectably varying the spacing between the fastener engaging aperturesof a jumper strip.

Other objects and features will be pointed out in the followingdescription and claims and illustrated in the accompanying drawingswhich disclose, by way of example, the principle of the invention andthe best mode contemplated for carrying it out.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings FIG. 1 is a top planview of a deflectable jumper strip constructed in accordance with theconcepts of the invention.

FIG. 2 is a front elevational view of the device of FIG. 1.

FIG. 3 is a fragmentary top plan view of a terminal strip which may beemployed in conjunction with the device of FIG. 1.

FIG. 4 is afragmentary top plan view showing a method of assembling thedevice of FIG. 1 to the terminal strip of FIG. 3.

FIG. 5 is a fragmentary top plan view showing the device of FIG. 1assembled to the terminal strip shown in FIG. 3.

FIG. 6 is a fragmentary top plan view showing a further embodiment of adeflectable jumper strip constructed in accordance with the concepts ofthe invention.

FIG. 7 is a fragmentary front elevational view of the device of FIG. 6.

FIGS. 8 and 9 are top plan views of further embodiments of a jumperstrip constructed in accordance with the concepts of the invention.

Similar elements are given similar reference characters in each of therespective drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIGS. 1 and 2there is shown a resiliently deflectable jumper strip 20 constructed inaccordance with the concepts of the invention. For electricalapplications, the strip 20 may be manufactured preferably fromelectrically conducting flat resilient metallic stock stamped or formedessentially in the shape shown. As illustrated, the strip 20 comprises abody member 22 comprising a pair of generally flat fastener engagingportions 24, 26 respectively, joined together by an upstandingresiliently deflectable arched portion 28. The arched portion 28 may bedeflected outwardly or inwardly as shown for example, by the dottedoutlines 30 and 32, respectively, in FIG. 2 either manually or by theuse of a suitable tool (not shown). Each of the fastener engagingportions 24, 26 comprises a fastener receiving aperture 34, 36,respectively. Joining each of the apertures 34, 36 to a common edge 38of the strip 20 is a slot 40, 42, respectively. In the embodimentillustrated in FIGS. 1 and 2, the bisecting axes of the slots 40, 42shown respectively as 44, 46, are each offset from the center line ofits associated fastenern'eceiving aperture 34, 36 by a distance shown asT1, T2, respectively, the distance T3 between the axes of the respectiveslots 40, 42 being shown in this case as greater than the distance T4between the centers of fastener receiving apertures 34, 36. Thearrangement may, of course, be reversed wherein the distance T4 betweenthe centers of the adjacent apertures is greater than the distance T3between the axes of the respective slots. Consequently, the strip 28 maybe disposed adjacent a pair of terminals 48, 50 (See FIG. 3) attached toa terminal block 52, the terminals 48, 50 being disposed on centersspaced apart, for example, a distance equal to T4, and urged intoengagement with the terminals 48, 50 by deflecting the arched portion 28inwardly so that the sides thereof approach one another as shown, forexample, by the dotted outline 32 whereby the axes 44, 46 defining therespective centers of the slots 40, 42 are brought into coincidence withthe shanks of the terminals 48, 50 so that the terminals may be advancedfreely through the slots 48, 42 and into engagement with the fastenerreceiving apertures 34, 36. By releasing the arched portion 28, thestrip 20 tends to assume its original shape thereby locking the strip 20against the terminals 48, 50. The terminals 48, 50 may then be tighteneddown to more securely hold the strip 20 thereto. To disengage thestrip20 from the terminal block 52 it is then merely necessary to loosen theterminal screws 48, 50 and deflect the arched portion 28 inwardly untilthe slots 40, 42 coincide with the spacing between the terminals 48, 50whereby the strip 20 may then be urged outof engagement with theterminals. As illustrated in FIG. 5, the assembly of the strip 20 to theterminals 48, 50 provides a direct connection therebetween and due tothe locking action provided enables the user to loosen each of theterminal fasteners 48, 50 to insert further conductors thereunder, ifnecessary or desirable, while being assured of the continued engagementof the strip 20 with the terminals 48, 50, during this operation. Therelationship between the slots 40, 42 of the strip 20 and the terminalscrews 48, 50 of the terminal block 52 prior to the assembly of thestrip to the board is shown more clearly in FIG. 4. By providing arelatively large opening between the slots 40, 42 and the common edge 38of the strip 20, which edge 38 tapers smoothly as at 54, 56 (FIG. 1) tothe necked down portion of the slot 40, 42, the assembly of the strip 20to the terminals 48, 50 may be accomplished in an alternative manner,that is, by urging the strip 20 against the terminal screws 48, 50 in adirection indicated by the arrow 58 in FIG. 4 whereby the pressure ofthe tapered surfaces 54, 56 against the shank of the screws 48,50 willcause the fastener engaging portions 24, 26 to be urged towards oneanother clue to the resiliency of the arched portion 28 therebetween sothat the terminal screws 48, may enter the slots 40, 42 in the strip 20and be advanced to the fastener receiving apertures 34, 36 at which timethe strip 20 will tend to spring outwardly to its original state causingthe strip 20 to be locked to the terminal screws 48, 50 as describedhereinabove. By reversing the offset relationship between the fastenerreceiving apertures 34, 36 and the slots 40, 42, that is, where thedistance between the axes 44, 46 of the slots 40, 42, respectively, isless than the distance between the centers of the fastener receivingapertures 34, 36, the outer edges of the slots 40, 42 bear against theshank of the respective screws 48, 50 causing the fastener receivingportions 24, 26 of the strip to be deflected away from each other duringassembly of the strip to the terminal block and then returned to theiroriginal state after the shank of each of the screws 48, 50 has enteredits respective fastener receiving aperture.

Referring now to FIGS. 6 and 7 there is shown a further embodiment of adeflectable jumper strip constructed in accordance with the concepts ofthe invention. The strip 60 may be of almost any length and comprises aplurality of preferably similarly dimensioned fastener receivingapertures 62 disposed in alignment along a common longitudinal axis,each of the fastener receiving apertures 62 being joined to a commonedge 64 of the strip 60 by a slot 66 having smoothly tapering sides 68,70. Between each pair of fastener receiving apertures 62 extendingtransversely through their respective fastener engaging portions 72 isan upstanding resiliently deflectable arched portion 74 similar toelement 28 illustrated in FIGS. 1 and 2. In this arrangement, however,the axes of the slots 66 coincide with the centers of the respectiveapertures 62 which are shown separated by a distance T5. When employedin conjunction with a terminal block such as 52 illustrated in FIG. 3,the distance T5 is arranged to be either slightly greater or slightlyless than the distance T4 between the terminal screws 48, 50. In thisway, each pair of fastener receiving portions 72 may be deflected eitherslightly inwardly or slightly outwardly, depending upon the particulardimension of T5, to cause the slots 66 to coincide with the respectiveshanks of the terminal screws 48, 50, and the strip thereafter urgedagainst such terminal screws until their shanks are seated within theapertures 62 of the strip 60. The strip 60will then tend to return toits original undeflected state urging the side walls of the apertures 62against the shanks of the respective terminal screws 48, 50 to lock thestrip in position thereat. The strip 60 may thus be employed tointerconnect three or more adjacent terminals to one another in a mannersimilar to that set forth above with respect to the embodimentillustrated in FIGS. 1 and 2. Since many terminal blocks now in commonuse are generally constructed with relatively standard center to centerterminal spacings, the fabrication of a strip such as 60 with suitablyspaced apertures becomes a simple matter of determination to provide thelocking action described hereinabove. The strip 60 may be furthermodified wherein given sets of apertures 62 are spaced on centersequivalent to the spacing T4 between terminal screws such as 48, 50, andother sets of apertures 62 on the strip 60 are spaced on centersdifferent than the spacing T4 between the terminal screws 48, 50 whereit may be necessary or desirable to reduce the force required toassemble the strip to the terminal block. It has been found that avariation in the spacing between the fastener receiving apertures 62 andthe spacing between the terminal screws 48, 50 in the order of from tento twenty thousandths of an inch is generally sufficient to provide thenecessary locking action.

Referring now to FIGS. 8 and 9, the deflectable upstanding archedportion 28 and 74 illustrated respectively in FIGS. 1 and 6 may bemodified to provide, for example, two spaced arched portions such as 76,78 illustrated in FIG. 8, or a relatively narrow arched portion 80spanning less than the full width of the jumper strip. Additionally,although the arched portions described heretofore have been shown asintegral with the remainder of the jumper strip, such portions may befabricated independently of the remainder of the jumper strip, and ofdifferent material where, for example, greater resiliency is desired,and such arched portion fastened to the fastener engaging portions bysoldering, welding, brazing, or the like, to provide the necessaryintegrity therebetween.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

l. A deflectable jumper strip comprising: a body member formed fromgenerally flat, resilient metallic stock, said body member having a pairof generally flat fastener engaging portions lying in a common firstplane and coupled together by at least one resiliently deflectableupstanding arched portion having sides extending generally parallel to asecond plane which is disposed substantially perpendicular to said firstplane, said arched portion being disposed intermediate said fastenerengaging portions, there being an aperture extending transverselythrough each of said fastener engaging portions, said apertures havingcenters spaced a first given distance from one another when said archedportion is in an undeflected state, and a second given distance from oneanother when said arched portion is selectively deflected, there being aslot joining each of said apertures with a common edge of said jumperstrip, the axis bisecting each of said slots and lying in said firstplane being selectively offset from an axis parallel to said slotbisecting axis and passing through the center of a corresponding one ofsaid body member apertures and lying in said first plane so that byselectively deflecting said body member arched portion, said slots maybe aligned with and cooperatively coupled to terminals disposed oncenters spaced from one another a distance generally equivalent to saidfirst given distance, wherein upon the release of said arched portion,said apertures are caused to be aligned with and cooperatively coupledto such terminals, said slots thereby restricting the removal of saidjumper strip from such terminals prior to redeflection of said archedportion.

gether by two of said arched portions.

1. A deflectable jumper strip comprising: a body member formed fromgenerally flat, resilient metallic stock, said body member having a pairof generally flat fastener engaging portions lying in a common firstplane and coupled together by at least one resiliently deflectableupstanding arched portion having sides extending generally parallel to asecond plane which is disposed substantially perpendicular to said firstplane, said arched portion being disposed intermediate said fastenerengaging portions, there being an aperture extending transverselythrough each of said fastener engaging portions, said apertures havingcenters spaced a first given distance from one another when said archedportion is in an undeflected state, and a second given distance from oneanother when said arched portion is selectively deflected, there being aslot joining each of said apertures with a common edge of said jumperstrip, the axis bisecting each of said slots and lying in said firstplane being selectively offset from an axis parallel to said slotbisecting axis and passing through the center of a corresponding one ofsaid body member apertures and lying in said first plane so that byselectively deflecting said body member arched portion, said slots maybe aligned with and cooperatively coupled to terminals disposed oncenters spaced from one another a distance generally equivalent to saidfirst given distance, wherein upon the release of said arched portion,said apertures are caused to be aligned with and cooperatively coupledto such terminals, said slots thereby restricting the removal of saidjumper strip from such terminals prior to redeflection of said archedportion.
 2. A deflectable jumper strip as defined in claim 1 wherein thecenter to center distance between said aperture is less than the centerto center distance between said corresponding slots.
 3. A deflectablejumper strip as defined in claim 1 wherein said fastener engagingportions are coupled together by two of said arched portions.